laravel-ascend

<?php declare(strict_types=1); namespace GoldenPathDigital\LaravelAscend\Server\Mcp\Config; use Psr\Log\LoggerInterface; use Psr\Log\NullLogger; use RuntimeException; final class FileWriter { /** @var string */ private $filePath; /** @var string */ private $configKey; /** * @var array<string, array<string, mixed>> */ private array $servers = []; private LoggerInterface $logger; /** * @param string $filePath Path to MCP configuration file * @param string $configKey Configuration key to modify (default: 'servers') * @param LoggerInterface|null $logger Optional logger for security events * @throws RuntimeException If file path contains path traversal or is not a JSON file */ public function __construct( string $filePath, string $configKey = 'servers', ?LoggerInterface $logger = null ) { $this->logger = $logger ?? new NullLogger(); $this->validateFilePath($filePath); $this->filePath = $filePath; $this->configKey = $configKey; $this->logger->debug('FileWriter initialized', [ 'file_path' => $filePath, 'config_key' => $configKey, ]); } /** * @param array<int, string> $args * @param array<string, string> $env */ public function addServer(string $key, string $command, array $args = [], array $env = []): self { $this->servers[$key] = array_filter([ 'command' => $command, 'args' => $args, 'env' => $env, ]); return $this; } /** * Persist the server configuration to disk. */ public function save(): string { $this->ensureDirectoryExists(); if (!is_file($this->filePath) || trim((string) file_get_contents($this->filePath)) === '') { $payload = [ $this->configKey => $this->servers, ]; $this->writeJson($payload); return $this->filePath; } $contents = file_get_contents($this->filePath); if ($contents === false) { throw new RuntimeException(sprintf('Unable to read MCP configuration: %s', $this->filePath)); } $decoded = json_decode($contents, true); if (json_last_error() === JSON_ERROR_NONE && is_array($decoded)) { $decoded[$this->configKey] = array_merge( $decoded[$this->configKey] ?? [], $this->servers, ); $this->writeJson($decoded); return $this->filePath; } $updated = $this->injectIntoJson5($contents); $this->writeRaw($updated); return $this->filePath; } private function ensureDirectoryExists(): void { $dir = dirname($this->filePath); if (is_dir($dir)) { return; } if (!mkdir($dir, 0755, true) && !is_dir($dir)) { throw new RuntimeException(sprintf('Unable to create directory for MCP configuration: %s', $dir)); } } /** * @param array<string, mixed> $payload */ private function writeJson(array $payload): void { $encoded = json_encode($payload, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES) . PHP_EOL; $this->writeRaw($encoded); } private function writeRaw(string $contents): void { if (file_put_contents($this->filePath, $contents) === false) { throw new RuntimeException(sprintf('Failed to write MCP configuration: %s', $this->filePath)); } } private function injectIntoJson5(string $contents): string { $pattern = '/["\']' . preg_quote($this->configKey, '/') . '["\']\s*:\s*\{/m'; if (preg_match($pattern, $contents, $matches, PREG_OFFSET_CAPTURE)) { [$match, $offset] = $matches[0]; $openBrace = strpos($contents, '{', $offset); if ($openBrace === false) { return $this->appendConfigSection($contents); } $closeBrace = $this->findMatchingBrace($contents, $openBrace); if ($closeBrace === null) { return $this->appendConfigSection($contents); } $existingSection = substr($contents, $openBrace + 1, $closeBrace - $openBrace - 1); $existingSection = rtrim($existingSection); $injection = $this->buildServersJson($this->detectIndentation($contents, $openBrace)); if ($existingSection === '') { return substr($contents, 0, $openBrace + 1) . PHP_EOL . $injection . PHP_EOL . substr($contents, $closeBrace); } $needsComma = !preg_match('/,\s*$/', substr($contents, 0, $closeBrace - 1)); if ($needsComma && trim(substr($contents, $openBrace + 1, $closeBrace - $openBrace - 1)) !== '') { $contents = substr_replace($contents, ',', $closeBrace - 1, 0); $closeBrace++; } return substr($contents, 0, $closeBrace) . PHP_EOL . $injection . PHP_EOL . substr($contents, $closeBrace); } return $this->appendConfigSection($contents); } private function appendConfigSection(string $contents): string { $injection = '"' . $this->configKey . '": {' . PHP_EOL . $this->buildServersJson(4) . PHP_EOL . '}' . PHP_EOL; $position = strpos($contents, '{'); if ($position === false) { return '{' . PHP_EOL . $injection . '}' . PHP_EOL; } return substr_replace($contents, $injection, $position + 1, 0); } private function buildServersJson(int $indentSize): string { $indent = str_repeat(' ', $indentSize); $segments = []; foreach ($this->servers as $key => $config) { $encoded = json_encode($config, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES); $encoded = str_replace("\r\n", "\n", (string) $encoded); $lines = explode("\n", $encoded); $first = array_shift($lines); $segments[] = $indent . '"' . $key . '": ' . $first; foreach ($lines as $line) { $segments[] = $indent . str_repeat(' ', 2) . $line; } } return implode(',' . PHP_EOL, $segments); } private function detectIndentation(string $contents, int $position): int { $lineStart = strrpos(substr($contents, 0, $position), PHP_EOL); if ($lineStart === false) { return 4; } $line = substr($contents, $lineStart + 1, $position - $lineStart - 1); $spaces = strlen($line) - strlen(ltrim($line, " \t")); return $spaces > 0 ? $spaces : 4; } private function findMatchingBrace(string $contents, int $openPosition): ?int { $depth = 0; $length = strlen($contents); for ($i = $openPosition; $i < $length; $i++) { $char = $contents[$i]; if ($char === '{') { $depth++; } elseif ($char === '}') { $depth--; if ($depth === 0) { return $i; } } } return null; } /** * Validate that the file path is safe and appropriate for MCP configuration. * * @throws RuntimeException If path is invalid */ private function validateFilePath(string $filePath): void { // Check for path traversal attempts if (str_contains($filePath, '..')) { $this->logger->warning('Path traversal attempt in FileWriter', [ 'file_path' => $filePath, 'violation' => 'contains_dotdot', ]); throw new RuntimeException('File path cannot contain ".." (path traversal detected)'); } // Ensure it's a JSON file if (!str_ends_with($filePath, '.json')) { $this->logger->warning('Invalid file extension in FileWriter', [ 'file_path' => $filePath, 'violation' => 'not_json', ]); throw new RuntimeException('File path must point to a .json file'); } // Extract filename to check for common MCP config names $fileName = basename($filePath); $validNames = ['mcp.json']; if (!in_array($fileName, $validNames, true)) { // Allow other names but ensure they contain 'mcp' for safety if (!str_contains(strtolower($fileName), 'mcp')) { $this->logger->warning('Suspicious file name in FileWriter', [ 'file_name' => $fileName, 'violation' => 'not_mcp_config', ]); throw new RuntimeException(sprintf( 'File name "%s" does not appear to be an MCP configuration file', $fileName, )); } } $this->logger->debug('File path validated successfully', ['file_name' => $fileName]); } }